Vacuum work pick-up attachment for work device

ABSTRACT

A work pick-up vacuum cup on the forward end of an elongated tubular arm is connected by a pipe to the throat of a venturi tube on the rearward end of the arm. The opposite ends of the venturi tube are connected to compressed air inlet and outlet couplings which in turn are connected to flexible air hoses. The arm is mounted in and projects outward from the opposite ends of the horizontal bore of a head having a vertical socket and replaces the work-lifting arm and head on top of the verticallyreciprocating horizontally-turning lift piston rod of the Lifting and Swinging Work Transfer Device of Kirsch et al., U.S. Pat. No. 3,406,837 of Oct. 22, 1968. The air outlet coupling has an auxiliary air outlet orifice for enhancing rapid release action. In a modification (FIG. 3), the forward end of the elongated tubular arm carries a plurality of such vacuum cups similarly connected to the throat of the venturi tube.

United States Patent Winne Mar. 14, 1972 [54] VACUUM WORK PICK-UP ATTACHMENT FOR WORK DEVICE [72] Inventor: John R. Winne, Detroit, Mich.

[73] Assignee: Erie Engineering Company, Troy, Mich.

[22] Filed: Apr. 3, 1970 [21} Appl.No.: 25,332

[52] U.S. CI. ..2l4/1BH, 294/64 A Primary Examiner-Gerald M. Forlenza Assistant Examiner-George F. Abraham Attorney-Barthel & Bugbee ABSTRACT A work pick-up vacuum cup on the forward end of an elongated tubular arm is connected by a pipe to the throat of a venturi tube on the rearward end of the arm. The opposite ends of the venturi tube are connected to compressed air inlet and outlet couplings which in turn are connected to flexible air hoses. The arm is mounted in and projects outward from the opposite ends of the horizontal bore of a head having a vertical socket and replaces the work-lifting arm and head on top of the vertically-reciprocating horizontally-turning lift piston rod of the Lifting and Swinging Work Transfer Device of Kirsch et al., U.S. Pat. No. 3,406,837 of Oct. 22, 1968. The air outlet coupling has an auxiliary air outlet orifice for enhancing rapid release action. In a modification (FIG. 3), the forward end of the elongated tubular arm carries a plurality of such vacuum cups similarly connected to the throat of the venturi tube 3 Claims, 3 Drawing Figures PATENTEDMAR 14 I972 INVENTOR JOHN R. WI NNE 43W,

ATTORNEYS VACUUM WORK PICK-UP ATTACHMENT FOR WORK DEVICE In the drawings,

FIG. 1 is a top plan view of a vacuum work-pickup attachment for a work transfer device;

FIG. 2 is a side elevation, partly in central vertical section, of the work-pickup attachment of FIG. I, mounted on the work transfer device, with the housing at the rearward end thereof broker away to show diagrammatically a venturi tube in side elevation; and

FIG. 3 is a top plan view of a modification of the vacuum work-pickup attachment shown in FIGS. 1 and 2.

Referring to the drawing in detail, FIGS. 1 and 2 show a vacuum work-pickup attachment, generally designated 10, for a work transfer device, generally designated 12, shown in detail in the Kirsch and Robb U.S. Pat. No. 3,406,837 issued Oct. 22, I968 for Lifting and Swinging Work Transfer Device. The last-mentioned device is operated pneumatically by compressed air and has a cylinder 14 mounted on a base 16 which is bolted or otherwise secured to a support adjacent the machine, such as a forming press (not shown) served by the work transfer device 12. For the purposes of the present invention, it is believed sufficient to state that the device 12 has a piston rod 18 projecting upward from the top thereof which is capable both of rotation through a partial revolution and reciprocation vertically so as to rise and fall as well as swing horizontally in response to the operation of pneumatically actuated mechanism contained within the cylinder 14. This actuates the piston rod 18 to automatically swing a work-gripping arm into position over a workpiece, to descend into gripping engagement with the workpiece, to ascend while lifting the workpiece, to swing horizontally to a predetermined location, and there to descend and release the workpiece, all as described and shown in the said US. Pat. No. 3,406,837.

The vacuum work-pickup attachment is provided with an adapter head or arm holder 20 which is bored longitudinally at its lower end to receive the upper end of the piston rod 18 whereby to replace the work-gripping arm in the work transfer device of the said Kirsch et al., US. Pat. No. 3,406,837. The head 20 near its upper end is provided with a radial or transverse bore 22 which extends horizontally through the head 20 and receives an elongated tubular arm 24 which is counterbored at 26 at its forward end to receive a cup-shaped end cap 28 containing a socket 30. The end cap 28 is of the so-called cinch cap type and snugly fits and closes the end'of the counterbore 26. The latter communicates with a bore 32 extending throughout the tubular arm 24 and terminating at its rearward end in a counterbore 34.

Mounted within the socket is a hollow cylindrical adapter 36 having an L-shaped passageway 38, the transverse portion 40 of which is internally threaded toreceive the externally threaded stem 42 of a vacuum cup unit 44. The vacuum cup unit 44 consists of a flexible vacuum cup 46 of elastomeric material, such as natural or synthetic rubber or resilient plastic. The central portion of the vacuum cup 46 is apertured for the passage of the stem 42, the lower end of which is enlarged as at 48 to hold the vacuum cup 46 firmly against a hollow annular hub 50 through which the stem 42 passes. The hub 50 is stepped to fit and be held within the correspondingly stepped circular cup retainer 52 which in turn is secured to the lower side of the forward end of the tubular arm 24. The cup retainer 52 is bored in alignment with the correspondingly bored end cap 28 and hub 50 for the passage of the stem 42, the upper end of which, as previously stated, is threaded into the transverse portion 40 of the L-shaped bore 38.

The longitudinal portion 54 of the L-shaped bore 38 is counterbored and threaded as at 56 to receive the threaded forward coupling 58 onto which is threaded the forward coupling 60 on the forward end of a suction pipe 62. The rearward end of the pipe 62 is provided with a rearward coupling 64 which in turn is connected to a rearward coupling 66 threaded into the threaded forward bore 68 of a flanged connector cap 70. The connector cap 70 is externally-threaded and is threaded into the threaded counterbore 34. The connector cap 70 is also provided with a rearward bore 72 into which is threaded the forward end of a nipple 74. The rearward end of the nipple 74 is connected to the throat 75 of a venturi tube 77 within the housing 76 of a venturi tube unit 78. The venturi tube 77, shown diagrammatically in FIG. 2, has an air inlet portion 80 and an air outlet portion 82 to which are threadedly connected the air inlet and outlet fittings 84 and 86 respectively. The air inlet fitting 84 is threaded to receive the compressed air inlet coupling 88 connected to a flexible compressed air hose 90 leading to a source of compressed air (not shown). The air outlet fitting 86 in addition to its usual bore (not shown) is provided with a restricted-diameter auxiliary air orifice 92 connected thereto. The orifice 92, leads to the atmosphere and, as explained below in connection with the operation of the invention, facilitates the rapid release of the air and therefore the rapid release of the suction grip on the workpiece W (FIG. 2) when the flow of compressed air through the air inlet hose 90 is shut off. The air outlet fitting 86 is threaded to receive the coupling 94 connected to a flexible air outlet hose 96.

lnthe operation of the invention, let it be assumed that a workpiece W resting on or in a support S, such as a die within a forming press, is to be removed therefrom and transferred to another location by the vacuum work-pickup attachment 10. Let it also be assumed that the latter has been brought downward to a position where the vacuum cup 46 is in contact with the workpiece W and that compressed air is entering the venturi tube 77 of the venturi tube unit 78 from the air inlet hose 90 and is being discharged through the air outlet or discharge hose 96, thereby causing a suction or partial vacuum to be created within the throat 75 of the venturi tube 77. As a consequence, a partial vacuum or suction is created in the pipe 62 and in turn within the vacuum cup 46 by way of its stem 42, thereby creating a partial vacuum or suction within the vacuum cup unit 44. As a result, the vacuum cup 46 exerts a gripping action upon the workpiece W.

The work transfer device 12 is now operated in the manner disclosed in the above-mentioned Kirsch et al., U.S. Pat. No. 3,406,837, to cause the piston rod 18 thereof first to rise and thereafter to rotate, swinging the head 20 and arm 24 through an arcuate path to a location above the desired point of disposal of the workpiece W, for example, a conveyor, a tote box, or into another machine for performing additional operations upon the workpiece W. The direction of flow of compressed air through the air inlet hose 90 and fitting 84 is then reversed to break the vacuum, terminating the suctionproducing action of the venturi tube 77. Meanwhile, the outside air immediately enters the auxiliary air orifice 92 in the air outlet fitting 86 to assist in breaking the vacuum within the venturi unit 78 and consequently break the vacuum within the pipe 62, stem 42 and vacuum cup 46. As a result, the vacuum cup 46 of the vacuum cup unit 44 releases its suction grip upon the workpiece W, which thereupon falls under the force of gravity into the disposal means.

Compressed air is then admitted to the cylinder 14 of the work transfer device 12 by way of its control valve (not shown) to initially rotate the piston rod 18 and swing the arm 24 and vacuum cup unit 44 through an arcuate return path to its previous position above another workpiece W. The mechanism within the work transfer device 12 then causes the piston rod 18 thereof to descend, and consequently bring the vacuum cup unit 44 into contact with another workpiece which has subsequently been deposited on the support 12. Compressed air is then readmitted from the compressed air hose 90 and coupling 88 through the air inlet fitting 84 into the venturi unit 78, recreating a suction in the vacuum cup 46 so as to cause it to grip the next workpiece W. The cycle of operation then proceeds in the same manner as described above and does so indefinitely until the apparatus is shut off.

' The modified vacuum work-pickup attachment,tgenerally designated 100, shown in FIG. 3 is generally similar, up to the forward end of the elongated tubular arm 24, hence similar parts to those shown in FIGS. 1 and 2 are designated withthe same reference numerals. Mounted on the forward end of the arm 24 is a hollow manifold 102, the central portion 104 of which is connected to and communicates with the suction pipe or conduit 62. Radiating from the central portion 104 of the manifold 102 are hollow fingers 106 which at their outer ends are bored and threaded at 108 to receive the stems 1 of plural vacuum cups 112 of elastomeric material. This arrangement enables the several vacuum cups 112 to adapt themselves to the gripping of a workpiece with less regular or flat surfaces than the single vacuum cup 46 of FIGS. 1 and 2, and also exerts a greater gripping leverage on the workpiece by reason of their greater distances from the center 114 of the central portion 104.

The operation of the modified vacuum work-pickup attachment 100 is generally similar to that described above for the vacuum work-pickup attachment l0 and hence is believed to require no additional description beyond that just given.

In both forms of the invention it will be self-evident from FIG. 2 that the combined weights of the venturi tube unit 78 and of the flexible hoses 90 and 96 connected to the couplings 88 and 94 will tend to counterbalance the combined weights of the vacuum cup unit 44, and the portions of the arm 24 and pipe 62 and the workpiece W on the opposite side of the adapter head from the venturi tube unit 78.

Iclaim 1. A vacuum work-pickup attachment for installation upon the rotatable and reciprocable piston rod of a work transfer device, said attachment comprising a work transfer arm holder having a longitudinal bore therein adapted to fit the work transfer device piston rod for motion unitarily therewith and having a transverse bore therethrough,

a work transfer arm mounted in said transverse bore of said holder and extending therethrough in outwardly projecting relationship therewith on opposite sides thereof and having a forward end and a rearward end disposed on said opposite sides thereof,

a vacuum cup unit mounted on said forward end of said arm,

a suction-producing venturi tube device mounted on said rearward end of said arm, said device having an air inlet portion, and air outlet portion, and a restricted throat portion of smaller diameter than said inlet and outlet portions and disposed therebetween;

a suction conduit connecting said vacuum cup unit to said throat portion,

and means for connecting said air inlet portion to a source of compressed air.

2. A vacuum work-pickup attachment according to claim 1, wherein there is provided an auxiliary air orifice leading from the atmosphere into said venturi tube device independently of said inlet and outlet portions.

3. A vacuum work-pickup attachment, according to claim 2, wherein said venturi tube device has inlet and outlet fittings and hose couplings connected respectively to said inlet and outlet portions, and wherein said auxiliary air orifice is disposed in one of said fittings. 

1. A vacuum work-pickup attachment for installation upon the rotatable and reciprocable piston rod of a work transfer device, said attachment comprising a work transfer arm holder having a longitudinal bore therein adapted to fit the work transfer device piston rod for motion unitarily therewith and having a transverse bore therethrough, a work transfer arm mounted in said transverse bore of said holder and extending therethrough in outwardly projecting relationship therewith on opposite sides thereof and having a forward end and a rearward end disposed on said opposite sides thereof, a vacuum cup unit mounted on said forward end of said arm, a suction-producing venturi tube device mounted on said rearward end of said arm, said device having an air inlet portion, and air outlet portion, and a restricted throat portion of smaller diameter than said inlet and outlet portions and disposed therebetween; a suction conduit connecting said vacuum cup unit to said throat portion, and means for connecting said air inlet portion to a source of compressed air.
 2. A vacuum work-pickup attachment according to claim 1, wherein there is provided an auxiliary air orifice leading from the atmosphere into said venturi tube device independently of said inlet and outlet portions.
 3. A vacuum work-pickup attachment, according to claim 2, wherein said venturi tube device has inlet and outlet fittings and hose couplings connected respectively to said inlet and outlet portions, and wherein said auxiliary air orifice is disposed in one of said fittings. 